MySQL：從三個表中進行選擇？

Question

我對帶有三個表的MySQL查詢有疑問。 我想搜索一個名稱並獲取所有（甚至最好是第一個）電話號碼和電子郵件。 這是我的桌子：

Table 1, contact
==========
id | name
==========
1  | stefan
2  | michael
3  | andy
4  | bob

Table 2, phone
==============================
id | contact_id | phonenumber
==============================
1  | 1          | +1 434 434232
2  | 1          | +1 434 24234
3  | 2          | +1 89234
4  | 4          | +1 345345
5  | 4          | +1 434 7567567

Table 3, email
===============================
id | contact_id | emailaddress
===============================
1  | 1          | stefan@home.com
2  | 1          | stefan@work.com
3  | 1          | stefan@mars.com
4  | 4          | bob@anywhere.com
5  | 2          | michael@nothing.com

這是我的查詢，將MySQL發送到必殺技：

SELECT c.name, p.phonenumber, e.emailaddress
FROM contact AS c
JOIN phonenumber AS p ON c.id = p.contact_id
JOIN email AS e ON c.id = e.contact_id
WHERE c.name = 'michael'

當我只做一個連接時，它的工作原理如下：

SELECT c.name, p.phonenumber
FROM contact AS c
JOIN phonenumber AS p ON c.id = p.contact_id
WHERE c.name = 'michael'

有任何想法嗎？

謝謝

麥克風

Answer 1

嘗試這個：

SELECT c.name, p.phonenumber, e.emailaddress
FROM name_of_your_schema.contact AS c
JOIN name_of_your_schema.phone AS p ON c.id = p.contact_id
JOIN name_of_your_schema.email AS e ON c.id = e.contact_id
WHERE c.name = 'stefan'
LIMIT 1;

湯姆·L

Answer 2

嘗試

SELECT c.name, p.phonenumber, e.emailaddress
FROM contact c
INNER JOIN phone p ON c.id = p.contact_id
INNER JOIN email e ON p.contact_id = e.contact_id
WHERE c.name = 'michael'

Answer 3

要使每個聯系人僅獲得一個結果，您可能會以某種非常規的方式使用聚合。 我修改了@Emanuel Saringan的查詢：

SELECT c.name, min(p.phonenumber), min(e.emailaddress)
FROM contact c
left JOIN phone p ON c.id = p.contact_id
left JOIN emailaddress e ON c.id = e.contact_id
WHERE c.name = 'michael'
GROUP BY c.id

看到它在這里工作： http : //sqlfiddle.com/#!2/6a8700/2